Within wireless communication, efforts in improving existing systems are currently focused on specifying the so called 5th generation (5G) system architecture.
Disadvantages of existing systems, such as Long Term Evolution (LTE), Universal Mobile Telecommunications System (UMTS), Global System for mobile communications (GSM) and the like, include insufficiently efficient power consumption, insufficient capability of handling massive amounts of terminals, and insufficient data rates and coverage in various scenarios.
In an exemplifying scenario, a first radio network node is capable of beam-forming and broadcasts reference signals in a cell representing a coverage area of the first radio network node. A second network node, neighboring to the first radio network node, is also capable of beam-forming and does also broadcast reference signals in a cell representing a coverage area of the second radio network node. In order to reduce power consumption, the first and second radio network nodes may be configured to only sparsely transmit the reference signals, and when possible may be configured to transmit control information using beam-forming. In this scenario, a problem may be how to manage mobility of a user equipment, served by the first radio network node, due to missing reference signals from the second radio network node, which in particular occurs when the second radio network node attempts to save power.
To overcome this problem, it has been proposed to turn on the reference signals for the second radio network node when the user equipment is detected to be located at outskirts of a coverage area for the first radio network node. Then, the user equipment measures the signal quality for the second radio network node. Subsequently, the handover may be performed if the measurement of signal quality is above a threshold value for triggering handover. A disadvantage is that the reference signals consume power.